Araneae.it: the online Catalog of Italian spiders, with addenda on other Arachnid Orders occurring in Italy (Arachnida: Araneae, Opiliones, Palpigradi, Pseudoscorpionida, Scorpiones, Solifugae)

In this contribution we present the Catalog of Italian spiders, produced on the base of the available scientific information regarding spider species distribution in Italy. We analysed an amount of 1124 references, resulting in a list of 1670 species and subspecies, grouped in 434 genera and 53 families. Information on spider biodiversity in Italy has increased rapidly in the last years, going from 404 species at the end of XIX century, to 1400 in the 1990s, to the current 1670. However, the knowledge on the distribution of the Italian species is far from being complete and it seems likely that there are still new species to be found or described. The Italian spider fauna is characterized by the presence of a relevant number of endemic species (342). Concerning families, Linyphiidae show the highest number of species (477) and the highest number of endemics (114). Gnaphosidae (166) and Salticidae (144) follows in terms of species richness, while Dysderidae (72) and Agelenidae (38) follows as total number of endemics. Information regarding the regional distribution revealed great unbalance between Northern and Southern Italy, with very scarce records for some regions in the South. This work is accompanied by an online version freely available online at www.araneae.it, where all information is thoroughly detailed and regularly updated by the authors. Besides spiders, we also provide, the species lists of other Arachnid orders occurring in Italy (Opiliones, Palpigradi, Pseudoscorpionida, Scorpiones, Solifugae). The lists and the associated details are available in a dedicated section of the online version of the Catalog.